Detect IE version (prior to v9) in JavaScript

Question

I want to bounce users of our web site to an error page if they\'re using a version of Internet Explorer prior to v9. It\'s just not worth our time and money to

Answer 1

This works for me. I use it as a redirect to a page that explains why we don't like < IE9 and provide links to browsers we prefer.

<!--[if lt IE 9]>
<meta http-equiv="refresh" content="0;URL=http://google.com">
<![endif]-->

Answer 2

This approach to detecting IE combines the strengths and avoids the weaknesses of jKey's answer using conditional comments and Owen's answer using user agents.

• jKey's approach works up to version 9 and immune to user agent spoofing in IE 8 & 9.

• Owen's approach can fail on IE 5 & 6 (reporting 7) and is susceptible to UA spoofing, but it can detect IE versions >= 10 (now also including 12, which postdates Owen's answer).

  // ----------------------------------------------------------
  // A short snippet for detecting versions of IE
  // ----------------------------------------------------------
  // If you're not in IE (or IE version is less than 5) then:
  //     ie === undefined
  // Thus, to detect IE:
  //     if (ie) {}
  // And to detect the version:
  //     ie === 6 // IE6
  //     ie > 7 // IE8, IE9 ...
  // ----------------------------------------------------------
  var ie = (function(){
      var v = 3,
          div = document.createElement('div'),
          all = div.getElementsByTagName('i');
  
      while (
          div.innerHTML = '<!--[if gt IE ' + (++v) + ']><i></i><![endif]-->',
          all[0]
      );
      if (v <= 4) { // Check for IE>9 using user agent
          var match = navigator.userAgent.match(/(?:MSIE |Trident\/.*; rv:|Edge\/)(\d+)/);
          v = match ? parseInt(match[1]) : undefined;
      }
      return v;
  }());
  

This can be used to set useful classes to your document containing the IE version:

    if (ie) {
        document.documentElement.className += ' ie' + ie;
        if (ie < 9)
            document.documentElement.className += ' ieLT9';
    }

Note that it detects the compatibility mode being used, if IE is in compatability mode. Also note that IE version is mostly useful for older versions (<10); higher versions are more standards-compliant and it's probably better to instead check for features using something like modernizr.js.

Answer 3

var isIE9OrBelow = function()
{
   return /MSIE\s/.test(navigator.userAgent) && parseFloat(navigator.appVersion.split("MSIE")[1]) < 10;
}

Answer 4

if (!document.addEventListener) {
    // ie8
} else if (!window.btoa) {
    // ie9
}
// others

Answer 5

Use conditional comments. You're trying to detect users of IE < 9 and conditional comments will work in those browsers; in other browsers (IE >= 10 and non-IE), the comments will be treated as normal HTML comments, which is what they are.

Example HTML:

<!--[if lt IE 9]>
WE DON'T LIKE YOUR BROWSER
<![endif]-->

You can also do this purely with script, if you need:

var div = document.createElement("div");
div.innerHTML = "<!--[if lt IE 9]><i></i><![endif]-->";
var isIeLessThan9 = (div.getElementsByTagName("i").length == 1);
if (isIeLessThan9) {
    alert("WE DON'T LIKE YOUR BROWSER");
}

Answer 6

I do like that:

<script>
   function isIE () {
       var myNav = navigator.userAgent.toLowerCase();
       return (myNav.indexOf('msie') != -1) ? parseInt(myNav.split('msie')[1]) : false;
   }    
   var ua = window.navigator.userAgent;
   //Internet Explorer | if | 9-11

   if (isIE () == 9) {
       alert("Shut down this junk! | IE 9");
   } else if (isIE () == 10){
       alert("Shut down this junk! | IE 10");
   } else if (ua.indexOf("Trident/7.0") > 0) {
       alert("Shut down this junk! | IE 11");
   }else{
       alert("Thank god it's not IE!");
   }

</script>